I just went to
www.bmracing.com and looked at their shifters. B&M does not offer a dedicated Mustang Megashifter, so I was wrong. But they do offer a "Mustang console Hammer". This utilizes the factory cable, mounts in the factory console, but uses a B&M faceplate. Probably will run you a little more, but probably you won't have to buy an install kit. Check it out. Sounds like it may be the ticket for you.